Today i got broken li-ion Bosch PSR Select screwdriver.
Repair was very easy, access to battery (common 18650) great.
Less than 5 minutes and tool work like new.
Tip: Always when You come across dead li-ion battery inside any rechargeable device always:
- measure current drawn from battery when device not in use (failed battery might be caused by failed component on PCB drawing constant small current so for example after 3 days Your new battery will go bad again) – so this is very important step
- measure charge cut-off voltage – plug charger and make sure it not go over 4.2V on battery terminals – failed charging circuitry might also cause battery fail – and broke new battery after couple of charges